London, England (CNN) -- Al Gore has played down the significance of the row over a leaked document which has caused a rift between rich and poor countries at the U.N. climate summit in Copenhagen.

In an interview with CNN's Becky Anderson, the former U.S. Vice President said: "It's not unusual during international negotiations for there to be multiple texts that are floated or leaked. I think it ought to be kept in perspective. I wouldn't put too much emphasis on the leaked text this early in the process."

The draft document, known as the "Danish text," has provoked an angry reaction from developing countries who say the document places an unfair burden onto them to reduce their carbon emissions.

"There will be lots of effort to try and get texts and versions of the texts that all sides can agree and work from. This is not unusual at this stage," Gore said.

Gore is due to arrive in Copenhagen on Monday, ahead of high-level political talks which get underway Tuesday.

He said climate change was the most complex challenge ever to confront human civilization and climate change skeptics -- who have prospered in the wake of email leaks from a UK climate research center -- were living in an "era of unreality."

"All around the world we are seeing the consequences of global warming," Gore said.

"The entire north polar ice cap is melting before our very eyes. Mountain glaciers are melting rapidly in places all over the world with record storms, droughts, floods, fires and sea level increase."

Given the amount of scientific evidence Gore said it was "silly to have a discussion about phrases taken out of context from stolen emails written more than 10 years ago."

Skeptics continue to "seize on any kind of triviality they can and pull it out of context. I'm sure they'll continue to do that," Gore said.

Gore also leapt to the defense of the Danish government.

"From my point of view the Danish government hosting this conference has done an extraordinary job to try and ensure that the conference and the results turn out well."

He is confident that the U.S. Congress will pass the necessary legislation which will allow the U.S. government to provide leadership.

"One house of Congress has already passed the legislation and two committees in the Senate have done so. The sponsors of the bill believe they have the votes now for passage early next year."

But Gore says responsibilities to act on climate change extend further than Capitol Hill.

"This is not a political issue. It's not an ideological issue. It's a moral issue about our responsibility to safeguard future generations from truly catastrophic changes that scientists tell us will unfold if we fail to take action."